


The Claiming

by waywardelle



Series: brother-mates 'verse [1]
Category: Supernatural
Genre: Alpha!Dean, Alpha/Beta/Omega Dynamics, Alpha/Omega, Canon divergence - Baby 11x04, M/M, Presenting later in life!Omega, Season/Series 11, omega!Sam
Language: English
Status: Completed
Published: 2015-11-08
Updated: 2015-11-08
Packaged: 2018-04-30 14:07:10
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 6,843
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5166644
Author URL: https://archiveofourown.org/users/waywardelle/pseuds/waywardelle
Summary: <blockquote class="userstuff">
              <p>At age 32, Sam Winchester presents as an Omega. No one is more surprised than Dean, the Alpha who's been pining over his little brother all his life. Canon divergence after scene with Piper in 11x04, "Baby."</p>
            </blockquote>





	The Claiming

**Author's Note:**

> A/B/O fic is my guilty pleasure, so I thought I'd try my hand at it. Warning: this is pure smut, but I can't help but add a little bit of plot. In this fic, for simplicity, an Alpha gets a knot, an Omega gets slick, and a Beta is a human for all intents and purposes.

Dean is exhausted and grumpy as he lumbers back to his car. Striking out always puts him in a funk, even if his heart wasn’t really into the chase. He’d been sniffing around the beta Roadhouse all night, pouting over the brother missing by his side. The betas didn’t even glance at him, so he ended up drinking alone in the back, people watching. A disappointing night, for sure, without even Sam’s snarky comments to put a smile on his face.

Sam’s always been a good wingman; his beta scent is musky-sweet and unassuming, and it helps Dean form trust between him and other betas. As an Alpha, he's just as rare as Omegas (they're called AO’s by betas, the subset of people who either get a knot or get wet), so it makes betas nervous to be around him, and it often raises hackles. Even though betas never present as anything, regular humans for all intents and purposes, they still have good sniffers, and one whiff of his Alpha pheromones has them shrinking back, writing him off as just another lonely knothead. His beta brother’s presence helps tamper that, like if Dean has someone as sweet as his brother by his side, then he must be a good guy, too. He doesn’t feel too bad about the deceptive nature of it, because Dean is a good guy-- tries to be, at least, and he’s never slept with anyone who didn’t want it. He strikes out a lot more often than he leads Sam to believe because of it. 

Plus, he’s just always felt better with Sam in his line of vision, his musky scent close. The Alpha in him can’t help but see Sam as his mate, and he lives his life accordingly. Sam doesn’t mind too much, anyway. He knows Alphas are naturally territorial, and Sam is his, always has been. Omega or beta or not. 

“Mistakes were made,” he fibs jovially to Sam as he opens the door and slides into the front seat. He instantly smells someone new, someone he wasn’t expecting to be there, and they smell fucking incredible. Like those fancy autumn candles Sam likes so much, vanilla and baking spices, with a sharp hint of underlying musk. It’s making his mouth water, and he turns to look into the backseat when a pretty girl pops up.

“Who are you?” she asks, casting her bedroom eyes on him. He gives her a smile, but he’s confused-- once he gets a look at her, he knows it’s not her he’s smelling. The scent is pure omega, and this girl is clearly a beta. A pretty beta, but definitely not the source of his drool.

“That’s my brother,” Sam whimpers suddenly, out of sight. “D-Dean--”

Every hair on the back of Dean’s neck stands up, and he peers into the backseat. Sam is butt-ass naked, lying on his back, eyes glassy and unfocused. He looks like he went forty rounds with the beta girl, but still has an itch that needs to be scratched. He smells desperate, almost. Dean’s still-buzzed brain moves slowly to put the clues together-- Omega scent, beta girl, and the pounding in his blood he’s never felt before, like something vital clicked online. His dick is hardening fast, and he locks eyes with his little brother. 

“Sam,” he breathes, almost panting. He can hardly believe it, but his sniffer hasn’t misguided him yet. It’s his little brother smelling like every wet dream Dean’s ever had. 

“Something’s wrong,” Sam croaks, and then closes his eyes like he couldn’t care less about the half naked girl putting her clothes on on top of him. Or, like he’s too ashamed to look at what he’s done. Dean can’t decide, but he can tell Sam is finished, and that means this girl is encroaching on their territory. 

“Get out,” Dean growls at the blonde, and he starts rudely collecting the clothes she hasn’t put on yet. “Out, out, out. Don’t touch him!” he snarls as she bends to give Sam a goodbye kiss, barely restraining from guiding her with a firm hand around her arm. “Get the fuck out of here.”

She must comprehend the Alpha red Dean can feel lining his irises, the hue coloring his vision. Sam is bathed in this gorgeous white light, like he’s glowing, and Dean’s heart is absolutely pounding out of his chest. His, his brother is…

“Dean,” Sam bleats, as the girl slams the door behind her. Dean couldn't care less, but he gives her a look with his teeth bared for the rough treatment of his best girl. “I don’t know what’s happening.”

That makes two of them. Dean presented as an Alpha at sixteen, like all AO’s do, and it was almost agony to wait those four years for Sam’s presenting. He was so sure his brother would be an Omega, his Omega. They were made for each other in every other way, moved around each other like magnets, even their father knew that. Societal norms were both outside the life of a hunter and the culture of AO’s. A mate is sacred, no matter where an AO found one. They were made to love their family, their pack, first and foremost. They didn’t feel the need to look for much more. 

But Sam hadn’t presented as an Omega. He hadn’t presented as anything, and it had been a tender spot between them ever since. Sam wasn’t happy about it, either. He had told Dean once, with a couple fingers of whiskey in him, that Dean was the only place he’d felt like he belonged, and even that didn’t work out the way it should have. 

So, Dean has been carrying around this ache for his mate he doesn't know how to quench, one he doesn't really want to, because he's convinced Sam is it for him either way. Instead, he molded his life like Sam was his mate anyway, and Sam, well. He put up with it for a little while, but it was hard for a beta to understand the instincts of an AO. Eventually, resentful of Dean snarling at (and nearly killing) every person who came sniffing around him, Sam left for college to find his own way. He’d taken every piece of Dean’s heart with him, but the four years they were apart allowed Dean some perspective. 

He got over it as much as he could (not at all), and Sam got over resenting Dean’s nature, and the fact that he would never be able to match it. He accepted it, for the most part, and let Dean be his life-mate in almost every aspect, still needing the familiarity and belonging. Sam still doesn’t appreciate Dean baring his teeth at every woman that shows an interest, and almost killing every man, but Dean thinks a part of him likes it, likes knowing Dean would turn this world and the next upside down to keep him. Ten years and a lot of mistakes later, Sam is still the most important thing in Dean’s universe. Sam practically is Dean’s universe, everything else orbiting around him, insignificant details in the face of Sam’s happiness. 

“Tell me what happened,” Dean bites out, rolling down his window. Sam’s scent is so overwhelming, so incredible, he wishes he had a paper bag to huff in to. He can’t think with his brother smelling like every single thing Dean has ever wanted. 

“I, I was in the diner,” Sam starts, his voice scratchy and afraid. “Then I-- I don’t know, Dean. Can we drive? Please?” 

“Put your clothes on, and we’ll go,” Dean tells him, trying to be patient with his confused, scared mate. 

No. _Brother_. Not _mate_ , he mentally corrects himself. _Not yet._

Sam _isn’t_ his mate, and he won’t be until he recognizes it himself--one of the few protections Omegas have when they go into heat, which Dean strongly suspects is happening. Everything about an AO relationship hangs itself on the Omega’s knowing, loving, willing consent. The Omega chooses the Alpha, not the other way around. An Omega’s capitulation is their gift to the Alpha of their choosing, and it’s the most precious gift Dean can imagine receiving. Even if their biologies are compatible (like Sam and Dean), an Omega can still deny the privilege of becoming someone’s mate. Dean can’t think of anything he’s ever wanted more than to be given that privilege. He has wanted it nearly all his life: not just any mate, but his brother. He just didn’t dream it was possible. 

It occurs to him suddenly that it’s rare, but sometimes, an AO can miss their first presenting at sixteen, due to stress (which Sam was certainly under at sixteen, more stress than any sixteen year old should be) or hormonal imbalances. Sam is thirty-two, sixteen years after his missed presenting, so it seems like his cycle has come back around. Dean can’t believe it; he never even thought to hope for this. It feels like every nerve ending in his body is straining towards his brother. His mate, if Sam will have him once he figures out what’s going on. God, Dean hopes he can have him. He already owns Dean, has all his life. 

“Okay,” Sam relents, scrambling to follow Dean’s gruff order. Sam doesn’t know it, but he’s already responding to the Alpha in Dean. Before, Sam would have told him to go fuck himself if Dean was that rude to his date, and he would have stayed naked just to spite Dean. “We uh, we need to get to that hunt, anyway.”

Dean starts up the car as Sam drops over the front seat. Dean ducks to avoid one of his long legs swinging over, nearly passing out from the strong scent between Sam’s open legs. Fuck, Dean can smell him so fucking good this close. Sam’s slick hasn’t started (something that is only triggered by an Omega accepting a mate), so it’s bearable, but all Dean wants to do is bury his nose into Sam’s neck and take a big, comforting sniff of his brother-mate. He can’t, though. He won’t do that to Sam. It wouldn’t be right, and it wouldn’t feel as real to Dean. He wants Sam to discover it on his own, because he’s so fucking smart, and he’ll be upset if he isn’t the one to realize what’s happening. And Dean won’t say, “Sam, I’m your mate,” because he won’t coerce Sam’s hormone-addled brain; he won’t make Sam think that it’s Dean’s way or the highway. He wants to, though, really badly. He wants to skip this and go straight to the good stuff, but he’ll be damned if he denies them both Sam’s awakening. 

“We aren’t going on any hunt,” Dean grumbles, white-knuckling the wheel. God, he wants to reach over and take a hold of Sam’s hair, forcing his head to the side with the grip so Dean can run his nose up that long, pale stretch of neck just waiting for Dean’s claiming mate bite. “We’re going to find a motel.”

“What?” Sam demands, Dean watching him button his shirt, covering the acres of golden skin he wants to put his scent all over. Sam looks over at Dean for the first time, and Dean can see the gold in his irises-- the mark of an Omega, much like the red in Dean’s. “Dean, people are--”

“People are always dying, Sam! Excuse me if I’m a little concerned about my monk brother deciding to sleep with some random girl in the backseat!” 

Sam scowls. “Her name was Piper.”

That was the wrong thing to say. Dean is growling underneath his breath, completely without thought. He can’t make himself stop, either. He wants to rip that girl into shreds for touching his, his Sam. He doesn’t have the right to feel that way, yet, but he could barely stand people even _looking_ at Sam. He remembers that crazy Becky girl, the first time she met Sam, feeling on his chest. He stood there with his arms crossed, completely unamused. She’s real lucky Sam is the forgiving type, because he almost tore her limb from limb for drugging him and forcing him into marriage. 

Dean turns to look at him, his teeth bared. His throat is practically vibrating with the growling. “I don’t give a fuck if her name was Bob. We are stopping to sort this out, you hear me?”

Sam crosses his arms over his chest, stubborn. “Dean, sleeping with a girl is not front page news! I can hear you growling over there; you know I hate that. Stop it.”

“My word is final,” Dean snarls, balling his fist into Sam’s sleeve, vision going red again. His voice is distinctly Alpha-pitched, and Sam used to have an ear for that, and it would make him respond all the more negatively. 

Now, the gold in Sam’s eyes glimmers brightly, almost all the green and blue gone. He looks down at his lap, picking at the threads. “Okay,” he whispers.

“Sammy,” Dean tries again when his vision clears. He reaches across the bench seat to lace his fingers through his brother’s, marveling at the electricity between them. He loves to touch his brother, does it as much as he can, but the warmth that is usually between them feels like it’s been stoked into a blaze. They aren’t hand-holding people, really, but Sam’s posture relaxes when Dean gives his long fingers a squeeze. “I’m not trying to be a dick or pick a fight. I’m worried about you, and I want to figure this out. You know something is wrong; you said it yourself.”

Sam blinks at him for a minute, then relaxes further into the seat, spreading his legs. His scent becomes stronger again, and it makes Dean lightheaded. “You’re right,” Sam murmurs, eyes slipping closed. He hasn’t let go of Dean’s hand; if anything, his grip has tightened, hooking his fingers into Dean’s. Sam has always taken comfort in the physical affection Dean gives him, that they give each other, even if he rarely initiates it. Dean is the tactile one. “I’m exhausted, Dean.”

“C’mere,” Dean soothes, wanting nothing but to comfort his Omega. He feels like the world’s biggest prick for using his Alpha-voice on Sam, but he’s desperate and turned on and so in love with his brother, sometimes, he can’t tell up from down. He tugs on Sam’s hand until he gets the hint, and Sam scoots across the bench seat to bury his nose into Dean’s neck. “You’re all right, hey, Sam?” He smoothes Sam’s hair off his forehead, tucking the soft strands behind his ears, scratching at his scalp. “Get some more sleep, sweetheart. I’ll wake you up when we get there.”

Sam has always taken comfort in Dean’s scent, but this time is different. He can hear Sam’s inhales. They’re more than just breaths. Sam is scenting him without realizing it, letting the smell of his Alpha soothe him down into sleep. Dean’s growl changes into a contented purr, and Sam smiles against his neck. 

For the first time since he got in the car, Dean breathes easy. 

An hour later, he’s pulling into a Holiday Inn Express. It’s much nicer than the hotels they’re used to, and he wishes they were at the Bunker for this, but he’ll be damned if Sam goes through his first Heat in a place with water stains on the ceiling. 

“Wake up, little one,” he murmurs into Sam’s ear, tugging on his hair. 

Sam’s eyes blink open blearily, and he groans. “Ugh, I feel worse. What’s going on?”

“We’ll get you better,” Dean promises, dropping a kiss to his temple. “I’m gonna go get us a room. Stay here, okay?”

When Dean comes back out, there’s an Alpha leaning up against the passenger side, clearly speaking to Sam. The scent of an unmated Omega is like a siren call to Alphas, and he can smell the Alpha’s intent, and while he can’t blame him (Sam is the ideal Omega, strong and beautiful and so fucking smart), his vision instantly goes red. There’s no warning tinge, just straight blood-red Alpha, in a way that has never happened before. Dean has never had to defend his Omega, so the rage that washes through him is almost terrifying in its intensity. 

The Alpha must notice a new scent in the mix, because his cooing stops. His head pops up, and he sees Dean charging towards him.

“This your bitch?” The Alpha calls, grinning, like this all one big joke. “He don’t smell mated, man. Think I could give it a try?”

The Alpha’s eyes widen when Dean pulls the gun from his waistband. He clicks off the safety immediately, not fucking around with threatening. This Alpha is gonna move, now, or his brains are gonna be all over the sidewalk. 

“That bitch is my mate,” Dean growls, taking a few steps forward until the tip of his gun is pressed against the man’s heart. “And you’re gonna show him some fucking respect, because if he wasn’t like this, he could kill you in sixteen different ways with just his bare hands. Apologize.”

The Alpha kind of laughs, and that makes Dean’s trigger finger itchy. “He ain’t yours,” the Alpha challenges. The scent of an unmated Omega makes Alphas kind of stupid, but Dean can hardly believe the audacity of the man to keep going when a pistol is pointed at his chest. 

“You’re right,” Dean tells him, grinning at him in a way that shows all his teeth. “He ain’t mine. But he ain’t yours either, to sniff around and coo at like some fucking zoo animal. Apologize to my brother.”

“Man, you--”

Dean grabs the Alpha’s greasy hair and rams his face into the window so hard, he hears the guy’s nose break. “Fuck!” he shouts, going to cover his face. 

“Apologize,” Dean growls, yanking his face back by the hair, shaking him. Blood is spurting down his face, and the animal in Dean is satisfied with the sight. He presses his gun to the back of the Alpha’s neck. “You aren’t mated, huh? No fucking wonder, scumbag like you. Omegas are every bit as strong and powerful, and you’re gonna learn some respect for them tonight, or you’re gonna eat a bullet. Decide.”

Dean casts a glance into the front seat, where Sam is watching this with narrowed eyes. Dean can see his big brain working overtime, putting all the pieces together. They lock eyes for a moment, and Sam licks at his dry lips. “Alpha,” Sam mouths at him, his big beautiful eyes glowing gold, and the recognition unlocks something. Dean can suddenly smell Sam, so goddamn strong like Dean’s got his face buried in Sam’s ass, straight from the source. Dean nods at him, trying to smile, even as the piece of shit in Dean’s grip squirms and bleats out a, “s-sorry, let me go, sorry.”

Dean all but throws him across the parking lot. The Alpha lands on his ass ten feet away, and Dean points his gun straight at him. “You’ve got five seconds to get out of my sight,” and he keeps his gun trained on the man until he stumbles away.

He turns back to Sam, who’s clawing at the passenger door, trying to open it. Dean gets it open for him, and Sam tumbles out of the front seat, right into Dean’s arms. 

“Shit, Dean,” he moans, scrabbling for purchase along Dean’s body. Sam’s hands ball into fists, gripping the back of Dean’s jacket. Dean can hear his thick inhales, taking in his scent, his nose burying itself into Dean’s crotch, his armpits, his neck, where the scent is strongest. “You smell so fucking good. I--”

“Inside,” Dean says, all but dragging Sam’s lithe body towards their room. He stops at the door, hands shaking. Sam drapes himself against Dean’s back, and Dean can feel Sam’s hard cock pressing against him. The light finally blips green, and they both practically fall into the room. 

Dean kicks the door closed behind him, and they stare at each other in the afternoon light filtering in through the blinds. “Sam,” he starts, balling his hands into fists so he doesn’t go straight into tearing his clothes off. They have to talk about this, at least briefly, before anything can happen here. 

“You knew,” Sam breathes. “You knew I--”

“Knew you couldn’t be a muggle, Sammy,” Dean grins, trying to make his Omega smile. 

It works. Sam chuckles, sitting at the edge of the bed. He smoothes his hands down his jeans, jaw working, like he’s trying to speak but nothing is coming out. He bites his bottom lip, and then peers up at Dean, the gold lining his irises mesmerizing. 

“You smell so good, Sammy,” Dean tells him, dropping to his knees in front of his brother. “Can you tell me what that enormous brain of yours has figured out?” He places his hands flat on Sam’s thighs, and Sam hooks their fingers together, still smiling. 

“I hated being a beta,” Sam whispers finally, tapping the tips of his fingers against the back of Dean’s hands. “Felt all wrong, like something was missing. I could always smell you. I knew what you were the morning you woke up with a knot, and I thought to myself, ‘at least I belong here.’ I was convinced I was an Omega, because you were an Alpha, and I… I knew we belonged together.”

“Then why did you leave?” Dean asks, massaging his brother’s strong quads. 

“Had to,” Sam murmurs, licking at his dry mouth. “Had to find somewhere else to belong, because it was such a shock that I didn’t belong with you, either.”

Dean shakes his head. “You’ve always belonged with me.”

Sam’s smile deepens, his dimples carving craters in the light stubble on his face. “I thought you would take a mate,” he whispers finally. “AO’s have to, to feel complete. But you never did,” he says, the last part full of wonder.

“Didn’t matter that you weren’t an Omega, Sammy. You were still mine, and I was still yours.”

Sam’s hands go to Dean’s face, tracing the deep ridges next to his eyes. “And now?”

Dean shakes his head. “That’s up to you, sweetheart.”

They lock eyes, the bright gold around Sam’s irises spreading to color the whole palette. Sam pushes at Dean’s chest, silently asking him to give Sam some space. Dean does, settling back on his haunches. 

As Dean watches him, Sam slowly spreads his long, denim-clad legs into a beautiful vee where Dean knows he’d fit perfectly. “Mate,” Sam whispers, eyes flashing, and his scent is suddenly flooding the room. “Oh, god,” Sam moans, hiking his hips, and Dean can see a wet spot growing quickly under his ass. 

“Fuck,” Dean whispers, watching Sam’s hips undulate as his first slick is released. “Sam, are you sure? This is-- I’m not gonna let you go until you’re tied up tight.”

“God,” Sam whimpers, leaning back against his hands. “That’s all I’ve--”

Sam doesn’t have time to get the rest of the sentence out before Dean is on him.

Their lips crash together so hard, their teeth bang. The first taste of Sam is like cracking an ice cold beer on a hot day, his brother’s mouth everything he’s been wandering the earth searching for. His mouth is lush, wet, tongue strong and seeking, prying Dean’s lips open for a taste of him. Dean growls, snagging Sam’s bottom lip between his sharp teeth, going for the button of Sam’s pants immediately. 

“Take these off before I get out my knife,” Dean snarls, standing to wrench himself out of his clothes. Sam is barely coherent, fumbling with the buttons on his shirt. Dean helps by ripping it, the buttons flying around the room, pinging off the walls. 

He runs his hands over Sam’s body, the firm muscle under gorgeous olive skin, all Dean’s. He can feel his knot trying to form against the hard on he’s had for hours, and he presses the heel of his hand against it, moaning. He drops his pants to his ankles, and Sam slithers off the bed to his knees before Dean can think. 

Sam kisses up Dean’s thigh, running his hands over the little blonde hairs. His mouth is hot and damp, and his tongue darts out to lick at Dean’s heavy balls. “Let me suck you,” Sam begs, his hips working in unconscious little circles. “Let me taste this gorgeous Alpha cock, please,” he repeats, kissing up the underside of Dean’s dick. 

Dean grips himself at the base, both to stave off his knot and to direct himself to Sam’s swollen, pink mouth. “Look at you, on your knees for your Alpha.”

Sam moans, swirling his tongue around the crown of Dean’s cock. Dean is dripping precome, and Sam laps it up like a kitten. Dean taps the head of his dick against Sam’s lips. “Open,” he demands, and as soon as Sam does, Dean drives into the hilt, then holds there, fisting his hands into Sam’s hair. 

Sam chokes, eyes wide and wet. His knees are spread beautifully, hands behind his back, the perfect picture of submission. He swallows around Dean’s cock, thrusting his hips forward and back, like he’s somehow gaining friction from the molecules of air against his big, smooth Omega cock. 

“Hold still,” Dean growls, the vibration deep in his chest almost a purr of contentment. He draws his hips back, and it pops from Sam’s mouth with audible suction. “You’re beautiful, Omega.”

“Dean,” Sam moans, his voice scratchy from having Dean’s cock beating against the inside of his smooth throat. Sam doesn’t seem to be able to stop touching him. “You taste so good. Smell so good. How is this--”

“Missed your first cycle,” Dean murmurs, tracing the head of his cock against Sam’s dimples, lips. “Just like you, isn’t it Sammy, to make me wait, make me ache and pine for you all my life.”

“Why didn’t you ever take a mate,” Sam whispers, then moves forward to suck the head of Dean’s cock into his mouth, nursing at the head, like he can’t get enough of the taste of Dean’s precome. 

“You know why,” Dean grouses, hands in Sam’s hair again. “Know I can’t live without you. Know there’s no one else, could ever be anyone else more important than you, little brother.”

“Yes,” Sam groans, burying his face into Dean’s pubes, inhaling. “God, you smell-- smell like honeysuckle and,” he takes a deep breath, nuzzling against Dean’s hipbone, “apple pie,” he grins. “Typical.”

Dean smiles at him, raking his hands through Sam’s unruly hair. “On the bed, Omega.”

Sam scrambles up, unfolding his long body to follow Dean’s command. Before he can lie down, Dean grabs his face and kisses him, moving his mouth languidly against Sam’s. He pours every ounce of love, every lonely night, every ache Sam couldn’t yet soothe into that kiss, saying thank you, and I love you. So much, more than you’ll ever know. Then he pushes at Sam’s chest, laughing as Sam yelps. His body barely has a chance to bounce back up from the mattress before Dean is on him, fisting his hands into Sam’s hair, stabbing his tongue into Sam’s mouth for another taste. 

“Are you mine, Sam?” Dean asks, pulling away to look into his brother’s eyes. His hands trail down Sam’s body, rolling a hard nipple in his fingers, scratching down his stomach. He takes a hold of his brother’s gorgeous, big cock, stroking him firmly. Sam is already close, the first orgasm of a Heat always right near the surface. 

Sam throws his head back, long, gorgeous neck bared for Dean’s teeth. He sets them there, holding the strong tendon in his bite, jacking Sam’s cock with firm pulls up, like he’s milking the sweet-smelling come straight from his mate’s body. When Sam doesn’t answer, Dean bites harder, growling in warning. 

“Yes,” Sam moans, hiking his hips up into Dean’s hands. “Yes, Alpha.” Then he comes, back arching, eyes wide and unblinking, mouth dropped open in a silent yell. 

“That’s it,” Dean soothes, continuing to jerk Sam’s still-hard cock. He’ll stay hard for the entirety of their mating. He bends, licking the come off Sam’s flat stomach, then gets his teeth around a nipple and sucks. 

“You defending me in front of that Alpha was really hot," Sam murmurs, hands in Dean's hair. "I... He scared me. But then I smelled you, and I wasn't scared anymore." 

"I will always protect you," Dean murmurs, trailing his blood-heavy lips down his Omega's body. "Always defend you." He moves down farther, licking a hot line up Sam’s blood-red cock, nursing at the head. “Nothing is going to take you away from me. Nothing ever could, especially an idiot Alpha.”

“You’re an idiot Alpha,” Sam grins down at him, gorgeous golden eyes sparkling.

“Yeah,” Dean smiles back, getting his hands under Sam’s thighs, pushing them up and back until his knees are pressed against his shoulders. “But I’m your idiot Alpha.”

“Fuck, Dean, what are you--”

“Shhh,” Dean murmurs, trailing his fingers over Sam’s heavy balls, rubbing his thumb against the perineum. “Keep your legs back for me.”

Sam does, hooking his hands around the back of his thighs. “Don’t, don’t, I’m such a mess down there--”

He’s right. The clear, viscous fluid leaking from his ass is spread all over, the smell so strong and sweet that Dean’s head is spinning. He circles his thumb over Sam’s leaking, twitching hole, watching the way it clenches then relaxes in response. He’s never seen anything quite so gorgeous, his Omega’s body responding to his touch, like the flower that only opens when it sees midnight. He dips his thumb inside, and Sam’s hole swallows it up easily, like a hot knife sinking into butter. 

“Fuck,” he growls, pushing his face between Sam’s ass cheeks. “Look at you, Omega. Fuckin’ look at you, Jesus,” and he buries his tongue in that hole, chasing the sweet liquid heavy on his tongue. 

Sam all but howls, legs twitching, thrusting his ass up into Dean’s face. Dean’s tongue circles the tight rim, then plunges inside, and he sets his lips and teeth on the edge and starts sucking, demanding the liquid straight from the source. He pushes Sam’s thighs back with his own hands, and he feels the smooth muscle trembling under his palms. He knows he could do this for hours, lay Sam back and eat out his hole like a girl. And he will, one day, when this isn’t so new, when his dick isn’t demanding entrance. 

He pulls back with a sharp pop and sighs, satisfied like he just devoured his favorite meal. He replaces his tongue with two thick fingers, nudging them at the Omega’s hole, watching it clench then pout, relaxed. His fingers slide inside easily, and Sam yells, hoarsely, scrabbling for purchase along the bed sheet. 

“That feel good, sweetheart?” he asks, thrusting his fingers back and forth, using the pads of the digits to lave against the trembling insides of his brother. He draws his fingers back, brings forward another, pushing three into Sam. 

Sam’s toes curl from where they rest by Dean’s ears, and his mate is panting harshly, wide eyes staring down at Dean like he’s never seen him before. “I’ve never,” Sam starts, licking at his swollen mouth, “No one’s ever,” he tries again, then falls silent.

“No one’s ever been inside this gorgeous body?” Dean guesses, pressing up against the hot walls of Sam’s asshole until he feels a tiny little nub. He flicks at it with his middle finger, and Sam shouts, his dick jumping off his belly, and he comes. It arcs from his body, hitting his chin and dribbling down his chest and stomach. Sam is sobbing, hips thrusting forward and back, like he wants more but can’t stand it. 

“N-no,” Sam finally sighs, body going lax against the bed. “Never felt right.”

“Never been with a man?” Dean asks, finally removing his fingers from his brother’s hole, his dick giving an insistent throb at the squelch of wetness. 

“I didn’t say that,” Sam grins up at Dean, who is hovering over his brother. Sam is gorgeous, always has been, but something about him like this, his pupils dilated, sweat sticking hair to his forehead, wide mouth grinning up at Dean, he’s fucking irresistible. 

Dean grins back, bending down to suck a kiss against his brother’s puffy, red mouth. “Is that right, Omega? You been fuckin’ guys?”

“Only the ones that asked for it,” Sam murmurs against Dean’s mouth, licking at his lips for an extra taste of his Alpha. 

“After your Heat,” Dean starts, grabbing at Sam’s thighs again to push them back to his chest, “I want you to fuck me with that pretty Omega cock.”

“You do?” Sam gasps, wrapping his hands around his thighs to keep them up where Dean wants them. “I don’t-- _oh,_ fuck--” 

Dean sinks inside his Omega while he’s not paying attention, throwing his head back, growling. His brother is so hot inside, so fucking wet, and he takes Dean’s big Alpha cock like it’s nothing. He bottoms out quickly, burying his knees into the mattress, propping himself up on his elbows, forearms on either side of Sam’s head. He watches Sam’s face, the way his mouth is open, working on nothing but moans, the tight clench of his eyes screwed shut. Sam’s hips are working against his, in tight little circles, like he’s getting used to the feel of Dean inside him. Like he’s begging for more. 

“I want you in every way I can have you, Omega,” Dean whispers against his brother’s mouth, then kisses him hard, biting at his mouth. 

“Have me,” Sam pants against Dean’s lips, wrapping his long arms around Dean’s neck, spreading his thighs even wider from where they rest in the air. “Have me, Alpha, please--”

Dean draws his hips back, watching Sam’s face still. Then he pounds back in, the slick sound of Sam’s wet hole making him growl louder. He realizes he’s been purring almost non-stop, and he can hear Sam now, too, rumbling deep in his throat. 

“Makin’ such pretty sounds,” Dean slurs, pressing his lips against Sam’s cheekbone as he starts up a fast, unforgiving rhythm. They’re both close already, and Dean can feel the tingling at the base of his spine, signifying his knot’s expansion. He gets up on his hands, pushing his knees deeper into the bed and lets go, punching his hips back and forth, angling his thrusts to spark against his brother’s prostate. 

He knows he’s hit it when Sam growls, baring his teeth at Dean. For the first time, he isn’t a sweet Omega, but a furious AO, gorgeous and ferocious in taking his pleasure from his mate. He drills his hips up into Dean’s, matching each drive forward, and the slapping sound of their bare skin has Dean’s eyes rolling back into his head. 

“Fuck me, fuck me,” Sam demands, snapping his hips up as Dean pounds him down into the mattress. “Fuck me, make me come, Alpha, make me come, fuck--”

Dean gets a hand around Sam’s weeping dick, and with two pulls, Sam’s hands smack down into the mattress as he yells, his third orgasm taking him by force. Sam is sobbing, pulling at Dean’s ass to get him in deeper. 

“You ready?” Dean asks, feeling the expansion of his knot catching on Sam’s rim every time he pulls back. “Ready for my knot, pretty Omega?”

“Please,” Sam whines, wrapping his long legs around Dean’s waist. 

Dean sits back on his haunches, pressing his hips tightly against his brother’s. He gives Sam short little thrusts, watching his face, their eyes locked on each other. Sam’s are burning bright with contentment, and Dean can feel the haze of red rain over his vision. He bares his teeth and tosses his head back, gripping his brother’s thick thighs. He pulls out once more, then drives back in, and his knot settles into place with an audible pop. 

“Fuck,” they both cry, and Dean drops, exhausted, onto his brother’s chest. 

He comes back to himself a few seconds later, Sam’s hands carding through Dean’s sweaty hair. Dean’s hips are moving in little circles as his come pumps inside his mate’s body, and he shivers. He’s never knotted anyone before, always determined to uphold the sanctity of an AO bond, no matter how many betas had begged to know what it felt like. He’d been saving it, unknowingly, for this moment. For his brother. For only his mate, or no one at all. 

“Feel so good,” Dean moans against Sam’s sweaty chest, darting his tongue out to lick at Sam’s rosy pink nipple. “Feel so good, Sammy.”  


“Yeah,” Sam moans, rotating his hips like he can’t get enough. “S-so full, Dean.”

Dean raises himself up, back onto his elbows, grinning down at his brother. “You comfortable?”

Sam smiles at him, raising his head to press a kiss against Dean’s tattoo. He nods, his nose scraping against Dean’s sweaty sternum. “I’m okay,” he promises. “That was… intense.”

Dean grins back, smoothing a hand through Sam’s wild hair. “Think it’s something you’ll want to do again?”

Sam shoots him a look. “You trying to get rid of me?”

Dean laughs, pushing his hips forward and back so his knot tugs on Sam’s rim. His Omega groans, then purrs deep in his chest. “You ain’t going anywhere, mate.”

With some careful maneuvering, they end up on their sides, Sam’s back pressed against Dean’s chest, Dean’s arm wrapped firmly around Sam’s flat tummy. He can’t get his nose out of Sam’s hair, keeps sniffing at him, taking in great huffs of his Omega’s scent. It’s different now, just a little, with a hint of Dean in there. The Alpha in him is satisfied that his claim is evident, that wherever Sam goes, whoever he meets from now on will know he is spoken for. That everyone will know there is an Alpha out there who will kill to keep him safe, keep him his.

“You didn’t bite me,” Sam murmurs, tipping his head to the side so his neck is bared, showing Dean the gorgeous length he has yet to lay a claiming bite to. Sam is still purring, like he’s making up for lost time, and all he wants to do is make evident his contentment. 

“I didn’t know if you wanted me to,” Dean admits, carding the hair away from Sam’s neck. “It’s permanent, Sam.”

“Dean,” Sam sighs, sounding like his old, exasperated self, “there is nothing more permanent than the way I feel about you.”

Dean is still pumping come inside his mate, but it’s slower now, the fog lifting. Any bite is going to hurt Sam now, out of the fog of his heat. He relays this message to Sam, then trails his hand down his brother’s body, grasping his half-hard cock, the other hand toying with Sam’s nipples. His Omega is still in heat, so his erection goes back to full hardness in a second. Dean grinds his hips into Sam, giving him as much distraction as he can, then he sets his teeth at the meaty part of Sam’s neck and shoulder, biting until he tastes blood. 

Sam comes again, pressing hard back into Dean’s body, his teeth. There’s less of it this time, his fourth and final orgasm the crescendo at the end. Dean lets go, soothing his tongue along the bite, tasting Sam’s blood, already imagining the scar, and how much he knows he’s gonna be obsessed with his mark on his mate’s body.  


“I want one too,” he tells Sam as he finally pulls out, watching his come start to drool out of his brother’s lax little hole. “When you fuck me, I want you to mark me, too.”

Sam shifts, turning to face his brother, not giving a shit that he’s leaking everywhere. “I think I can manage that,” he smiles, and he is the most beautiful thing in Dean’s world, every sunrise and sunset, every bullet of the Colt, every purr of his baby’s engine. He lives by that smile, and he will die, gratefully, by that smile. 

“Do you love me, Alpha?” Sam wonders, trailing his long fingers along Dean’s neck, like he’s taking inventory of where he wants his bite to be. Then he buries his face in Dean’s chest, inhaling deeply, like he can’t stand not being able to smell him this close. Dean knows the feeling. 

“More than I know how to say,” he tells Sam, burying his hands in his Omega’s hair. 

Dean knows he will spend the rest of his life, however long or short that may be, trying to figure out a way to tell him.

**Author's Note:**

> As always, kudos and comments make my world go 'round. xoxo

**Works inspired by this one:**

  * [Always Yours](https://archiveofourown.org/works/13752006) by [TheSkyWriter](https://archiveofourown.org/users/TheSkyWriter/pseuds/TheSkyWriter)




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